1. Field of the Invention
The present invention relates to a ball retainer of a linear guide apparatus which includes a guide rail and a slider movable on the guide rail through rolling of balls interposed therebetween.
2. Description of the Prior Art
A prior art ball retainer of a linear guide apparatus of this type is disclosed, for example, in U.S. Pat. No. 4,253,709 (Japanese Patent Laid-Open Publication No. 55-72912).
As shown in FIGS. 9 and 10, the ball retainer 3 of a linear guide apparatus including a guide rail 1 and a slider 2 movably mounted on the guide rail 1 through rolling balls B is made of a thin steel plate. The ball retainer 3 is formed by stamping so that both sides have a wave form along the inner surface of the slider 2. In each of the sides of the wave form, a window 5 is formed having a width somewhat smaller than a diameter of the ball B and extending axially along the length of the ball retainer 3.
The retainer 3 is secured to the inner surface of the slider 2 by fixing screws 4, and the balls B mounted in the window 5 are held in ball rolling grooves 6 and 7 of the inner surface of the slider 2.
When the slider is linearly moved on the guide rail 1, many balls B roll in the ball rolling grooves 6 and 7 and in the ball rolling grooves 8 and 9 of both side surfaces of the guide rail 1.
However, in such a prior art linear guide apparatus, the ball retainer 3 is made of a thin steel plate, and the balls B are held in the ball rolling grooves 6 and 7 by ball holding stocks of the windows 5 formed in the sides of the ball retainer 3. As a result, the following problems are encountered.
It is necessary to remove one of the end caps at opposite ends of the slider 2 at the time of mounting the balls B in the ball rolling grooves 6 and 7 of the slider.
Furthermore, when the balls B are replaced to adjust a preload or the like, it is necessary to remove the end cap in the same manner, or the ball retainer 3 itself must be removed.
Accordingly, the work for mounting or demounting of the balls B to and from the ball rolling grooves 6 and 7 in the inside of the slider is inconvenient and troublesome, and further, it is impossible to automatically assemble.